Intake leaking 440????!?!?!?!?

just a note for you. every 383-400-440 produced used a metal valley pan without gaskets, and we are talking ten of thousands of them. I have built 20 or 30 big blocks and never used anything but a valley pan and never had sealing issues with a cast iron or aluminum intake. the gaskets are included in some kits in case you have an intake or heads that have already been milled. if you are not getting an air tight seal with or without sealer and gaskets, I would look hard at having a cracked intake or cracked head port. its possible that one or the other has already been milled but at a funky angle that is causing it to leak that the gaskets wont seal. I would definitely check the intake and head mating surface angles to see if they are the same. if it were me , I would toss another intake on there and see if that cures it, if anything, just to rule that out. you also want to keep the starting fluid or whatever you are using to check for leaks from getting sucked into the carburetor because that will also increase the idle speed. any open vacuum port or a bad carb seal to the intake will also result in the same increase. I don't think ive ever had one intake that sat perfectly flat on the engine that didnt sealed perfectly after torqueing it down. there is a bit of tolerance that can exist but still seal. that's all I can offer at this point.